2.0 Analysis 2.1 Introduction The pilot was certified and qualified for the flight. There was no evidence that physiological factors affected his ability to conduct the flight safely. No evidence was found of any pre-impact failure of the airframe or malfunction of either engine; all the damage to the aircraft was attributable to the impact. Due to the serious damage to the forward section of the aircraft caused by the impact, the accident was not survivable for the pilot and the front-seat passenger. The analysis will examine the possible explanations for the engine problems encountered during the take-off and climb, the single-engine handling and performance characteristics of the G21A aircraft type, and the loss of directional control. 2.2 Engine Problems During the Take-off and Climb 2.2.1 Engine Examination The cause of the engine problems encountered during the take-off and climb could not be determined. There was no evidence identified during the disassembly and examination of both engines which would preclude their normal operation or would prompt the pilot to feather the left propeller. The corrosion damage to the rotor, to the inside of the left engine-driven fuel pump, and near the points of the left magneto may have resulted from exposure to environmental conditions after the accident and would not have affected engine performance and operation prior to the occurrence. As evidenced by the tachometer indication of 1,300 rpm and the damage to the right propeller, the right engine was producing some power at impact. However, it could not be determined whether this lower-than-normal power output was due to the engine problems encountered during the take-off and climb, or was a result of the pilot reducing the power prior to impact. 2.2.2 Fuel Contamination There was sufficient fuel for the flight. There is no evidence indicating that fuel from the refuelling source was contaminated. It was not determined whether the aircraft fuel system had been drained and checked for contamination prior to the flight. Nonetheless, the method used by the company to check the fuel system for contamination was inadequate. It would likely not be possible to successfully check for relatively small amounts of water or other contamination by observing from the cockpit the puddle of fuel drained onto the ground. The amount of water found in the fuel tanks during aircraft examination may have been sufficient to cause an engine to run poorly or to malfunction. As the two fuel sample analyses produced conflicting results, the origin of that water could not be determined. Consequently, it could not be determined whether the fuel in the aircraft tanks was contaminated prior to the accident. However, it is possible that the water was present as a result of condensation that formed in the partially filled tanks after the occurrence. The traces of water found in the engines following the accident are not consistent with severe fuel tank contamination; moreover, it is unlikely that those traces of water would have been sufficient to cause an engine to run poorly or malfunction. 2.2.3 Carburettor Icing There was no evidence found of carburettor icing. However, the temperature and dew point at the time of the occurrence were conducive to serious carburettor icing at all engine rpm values. A reduction in engine rpm and power, as would have resulted from carburettor icing, may be consistent with the engine problems encountered during the take-off and climb, and the right engine running at 1,300 rpm at impact. However, it could not be determined whether carburettor icing affected either engine's performance or operation. 2.3 Aircraft Certification and Single-Engine Handling The aircraft was designed in accordance with 1937 certification standards. However, the aircraft does not meet current certification criteria established by modern regulations. The G21A reportedly has limited performance and poor flight characteristics during single-engine operations. Because of the 10 to 15 knots difference between the single-engine minimum control speed (Vmca) and the normal two-engine climb speed, immediate action is required in order to prevent the airspeed from decaying below Vmca should one engine become inoperative. If the airspeed decays below Vmca, the pilot should reduce power on the operating engine to maintain directional control and land straight ahead. Although the manuals used by the company for training on the G21A did not address the aircraft's handling characteristics, these preferred actions for single-engine handling were discussed and practised during the pilot's training. 2.4 Loss of Directional Control As the aircraft was not equipped with a flight data recorder and cockpit voice recorder, the actual position and altitude of the aircraft during the departure and the exact sequence of events could not be determined. However, the fact that the aircraft rolled to the left and descended rapidly to the ground indicates that directional control was lost soon after the left propeller was feathered. The loss of directional control to the left suggests, first, that the airspeed decayed below Vmca while power was maintained on the right engine and, second, that the preferred actions to maintain control of the aircraft in the event that the airspeed decays below Vmca after an engine failure during the initial climb were either not immediately taken or not effective. The pilot may have reduced power on the right engine prior to impact. It is also possible that the pilot experienced a complete engine failure while attempting to turn back with a rough running engine, and that the result of that engine failure caused the aircraft to rapidly lose airspeed to an extent that control was lost. 2.5 Emergency Locator Transmitter The ELT did not activate on impact because the switch on the unit was in the off position. The remote switch installed in the cockpit would not have been able to turn the unit on, nor would the automatic activation mechanism on the ELT have functioned following ground impact. 3.0 Conclusions 3.1 Findings The aircraft was certified, equipped, and maintained in accordance with existing regulations and approved procedures. The pilot was certified, trained, and qualified for the flight in accordance with existing regulations. Based on medical examination and medical records, there is no evidence to indicate that the pilot's performance was degraded by physiological factors. There was no evidence found of any airframe failure prior to or during the flight. The weight and centre of gravity were within the prescribed limits. One or both engines did not sound as if they were operating normally during the take- off and climb. The left propeller was feathered and directional control of the aircraft was subsequently lost. The cause of the engine problems encountered during the take-off and climb could not be determined. There was no mechanical problem that precluded normal engine operation. It could not be determined whether carburettor icing affected either engine's performance or operation. There is no evidence indicating that fuel from the refuelling source was contaminated. It was not determined whether the aircraft fuel system had been drained and checked for contamination prior to the flight. Procedures in use by the company pilots for daily fuel tank draining were not adequate to detect water or other contamination in the fuel system. As the analysis of the two samples produced conflicting results, the origin of the water found in the aircraft fuel tanks could not be determined. It could not be determined whether the fuel in the aircraft tanks was contaminated prior to the accident. Because of the 10 to 15 knots difference between the single-engine minimum control speed and the normal climb speed, immediate action is required in order to prevent the airspeed from decaying below Vmca should one engine become inoperative. The occurrence aircraft type did not meet design criteria established by modern regulations. The manuals used by the company for training on the G21A did not address the handling characteristics of the aircraft. The emergency locator transmitter did not activate on impact because the switch on the unit was in the off position. 3.2 Causes The pilot encountered engine problems during the take-off and climb, and, after the left propeller was feathered, lost directional control of the aircraft. The aircraft rolled to the left, descended rapidly, and crashed to the ground. The Board has no aviation safety recommendations to issue at this time.4.0 Safety Action The Board has no aviation safety recommendations to issue at this time.